1. Field of the Invention
Embodiments of the present invention generally relate to a doped aluminum nitride hardmask and a method of making a doped aluminum nitride hardmask.
2. Description of the Related Art
As semiconductor devices continue to shrink in size, the precision needed to form such small devices increases. It has become increasingly more difficult to not only shrink the size of the semiconductor chip, but additionally, the individual features that form the electrical interconnects.
There are numerous processes that are performed to fabricate a semiconductor chip. Patterning is one of those processes. In a patterning process, a mask, such as a hardmask, is formed over one or more layers to be patterned. Thereafter, utilizing the hardmask, the underlying layer or layers are exposed to an etchant so that exposed material (i.e., material not covered by the hardmask or photomask) is removed and the pattern of the hardmask is transferred to the underlying layer or layers.
In the ideal etching process, the exposed material is etched while the hardmask is not etched. In other words, the hardmask is ideally inert to the etchant, which may take the form of either a liquid etchant of a gaseous etchant. If the hardmask is inert to the etchant, then the features of the hardmask may transfer to the underlying layer or layers quite well.
Naturally, a chemically inert hardmask is not practical to manufacture. Therefore, some etching of the hardmask is expected. As the hardmask is etched, the precision of the pattern transfer is compromised.
Therefore, there is a need in the art for a hardmask that is more chemically inert to the etching process utilized to transfer the pattern from the hardmask to the underlying layer.